Improvement of river water storage in JUELS using high ... · Improvement of river water storage in JUELS using high resolution river-routing scheme Hee-sook Ji*, Ui-yong Byun**,

Improvement of river water storage in JUELS using high resolution river-routing scheme

Hee-sook Ji*, Ui-yong Byun**, Eun-chul Chang**, Yoon-jin Lim*, Yoon-jae Kim*

JULES Science Meeting, 4-6 Sep. 2018

*National Institute of Meteorological Sciences, Korea Meteorological Administration ** Kongju National University, Korea

[email protected]

Contents

Backgrounds - River Routing in Land Surface Model

Objective

Results - High Resolution TRIP ancillaries

- JULES-TRIP system

- Climatological river water storage

Future Plan

River Routing in Land Surface Model

Schematic of JULES soil-column highlighting stores and fluxes of water (Dadson et al., 2011)

• River discharge is one of the important components in the hydrological cycle, which transports precipitation to river basin outlets throughout river-routing processes.

* TRIP : Total Runoff Integrating Pathways scheme [Oki et al., 1998] * RFM : River Flow Model [Dadson et al., 2011]

• JULES has TRIP and RFM as river routing schemes that are used to route surface and sub-surface runoff from inland grid cells across the river network to river basin outlets.

TRIP river network map [Oki et al., 1998]

River Routing in Land Surface Model • The aim of TRIP is to provide a method for routing runoff from land surface to river basin

outlets to enable the validation of the runoff part of land-surface parameterizations in global climate models (GCMs).

• To run TRIP module, several ancillaries are required, such as river direction and river sequence, but there are only 1 and 0.5 degree horizontal resolution data (http://hydro.iis.u-

tokyo.ac.jp/~taikan/TRIPDATA)

• In addition, for a long term simulation and a coupled with climate model (for example, (KMA seasonal forecast model; Glosea5), river storage and river mouth data are also needed.

GloSea5

Objectives

• To implement a high resolution TRIP module to JULES modeling framework

- Generation of the 0.125 degree resolution ancillaries (river direction, river sequence) - Construction of JULES-high resolution TRIP

• To product climatological river water storage data for simulating long term period

Global River Direction & Sequence map river water storage ( log10kg m-2)

JULES -TRIP

32 64 128

16 1

8 4 2

8 1 2

7 9 3

6 5 4

* 9 means river mouth

River direction and Upstream drainage

1˚ X 1˚

TRIP DRT

0.5˚ X 0.5˚ 0.125˚ X 0.125˚

River Direction

• DRT(Global Dominant River Tracing , [Wu et al., 2012] ) data set is used for generating 0.125 degree resolution river directions.

• The DRT data set provides the river direction to the neighboring grids with resolutions from 1/16 to 2 degree, which is the most appropriate for the simple advection approach of TRIP.

• From the original DRT data set, which includes only river direction, we have added further information concerning grid points for the coastal river mouth and assigned individual identification numbers.

High Resolution TRIP ancillaries

High Resolution TRIP ancillaries River Sequence

• River sequence is the same concept as the river pathway number, and values of grids is increasing towards river mouths based on passing the number of grids.

River sequence map (0.125˚)

Concept of river sequence

Results

• Comparison of the different spatial resolution ancillaries

Evaluation

Han river

basin OBS

1.0°

×

1.0°

0.5°

×

0.5°

0.125°

×

0.125°

Mean

(kgs-1) 1552.2 7904.8 1934.4 1720.8

• The observed and simulated river discharge

Construction of JULES-TRIP System

JULES part

JULES-TRIP output (runoff and river flow rate)

TRIP part

Regridding of runoff (JULES grid to TRIP grid)

Regridding of runoff and river flow rate (TRIP grid to JULES grid)

TRIP resolution output (river storage and river discharge)

1°x 1°

1°, 0.5°, 0.125°

• In JULES-TRIP system, The river storage and discharge are calculated in TRIP using simulated runoff from JULES. After then runoff and river flow rate is re-simulated in JULES using calculated river storage and discharge.

* 2014.08.27 00UTC, river water storage ( 𝐥𝐨𝐠𝟏𝟎 kg m-2)

River storage data

1°x 1° 0.5°x 0.5° 0.125°x 0.125°

• Comparison of the different spatial resolution

2014. 8. 27 00UTC [29°N - 30°N, 111°E - 112°E]

River storage [ kg m-2]

1° x 1° 0.5° x 0.5° 0.125° x 0.125°

average 210.0

range 210

average 212.91

range 160~265

average 172.6

range 15~1149

• Storage conservation

River storage data

JULES part

JULES-TRIP output (runoff and river flow rate)

Precipitation data

Ancillary data

Other meteorological forcing data

TRIP part

Regridding of runoff (JULES grid to TRIP grid)

Regridding of runoff and river flow rate (TRIP grid to JULES grid)

TRIP resolution output (river storage and river discharge)

1°x 1°

1°, 0.5°, 0.125°

Generation of climatological river water storage

Processes

• Climatological river water storage has been simulated using reanalysis data during 1988-1997 in modified JULES. The reanalysis data are precipitation from

CPC and meteorological forcing from DA126.

Time series of the simulated river storage

Initial value “0”

1988 1989 1990 1991 1992 1993 1994 1995 1996 1997

Time (year)

1989 1990 1991 1992 1993 1994 1995 1996 1997

Bia

s (s

1988-s

1989)

rive

r w

ate

r st

ora

ge( kg m

-2)

River storage spin-up

case1 case2 case3

• About 2-year is suitable for spin-up period for generating climatological river

storage

Time (year)

Results

The simulated river storage during the period of 1990-1997

1°x 1° 0.125°x0.125°

Climatological river water storage on August (log10 kg m-2)

Summary and Future Plans

• JULES-high resolution TRIP(0.125 degree) has been developed. As a result, it is possible to get a high resolution river discharge data.

• The different source based climatological river water storage will be generated for a long term simulation and application studies.

• In addition, we will implement the 0.125 TRIP to GloSea5 system ((now) 1 -> (new) 0.125), and understand the interaction between atmosphere and ocean.

Thank You !